THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.

ANDERSON COOPER, CNN ANCHOR: Should police be able to stop you if they reasonably suspect you're an illegal immigrant? These protesters say no, but Arizona legislators say yes, and they have passed legislation to make it happen. Is it constitutional? We're "Keeping Them Honest."

Also tonight, the story behind these incredible pictures up close of that oil rig explosion. We will talk to the ship captain who took them and raced to the scene to try and help.

And, later, medical mistakes -- thousands, tens of thousands die every year because of them. And, often, doctors try to hush it up. They certainly don't want to talk about it. Well, tonight, we're going to talk to actor Dennis Quaid on the medical mistake that almost killed his newborn twins and his fight now to make sure that no parent ever goes through what he did.

First up tonight, "Keeping Them Honest": the new Arizona measure to curb illegal immigration by giving police the power to stop anyone they reasonably suspect is an illegal immigrant.

Want to take you over to the wall here and just show you some pictures that we put up on the wall over here. Take a look at these faces. Now, some of them belong to illegal immigrants or people who were in the country illegally at the time that we took the pictures.

Some are simply ordinary American citizens. Now, look closely. Can you tell the difference? Well, the new bill in Arizona -- let me just make this a little bigger here -- this is what it says. It says, "Where reasonable suspicion exists that the person is an alien who is unlawfully present in the United States, a reasonable attempt shall be made, when practicable, to determine the immigration status of the person."

"Reasonable suspicion," now, those two words are crucial. Now, in America, the police can stop you if they have probable cause that a crime has been committed, if you're driving erratically or they witness you dealing drugs, but just appearing like an illegal alien? Some supporters of the bill say police won't be judging based on race. Maybe they will be looking at clothing, shoes, for instance. They will be checking out what kind of shoes you have.

That's what Congressman Brian Bilbray said the other day. So, OK, same test. Here are some shoes. Can you pick the illegal immigrant footwear out of the bunch? Well, probably not. Senator John McCain supports this new bill. Let me move that down as well. Senator John McCain supports the bill, even though he once co-sponsored an immigration reform act with the late Senator Ted Kennedy. He's now in a tough primary battle against conservative opponent J.D. Hayworth.

Others, including the Arizona Association of Chiefs of Police, oppose it, saying it's a burdensome intrusion on a federal responsibility. And Roger Mahony, the archbishop of Los Angeles, calls it -- quote -- "the country's most retrogressive, mean-spirited and useless anti-immigrant laws."

You're going to hear from both sides of the debate tonight.

(BEGIN VIDEOTAPE)

COOPER: Joining us now is Arizona Republican State Representative John Kavanagh, a key architect of the bill.

Thanks for being with us.

Can you tell if someone is an illegal immigrant by looking at them?

JOHN KAVANAGH (R), ARIZONA STATE REPRESENTATIVE: Absolutely not.

COOPER: So, under this bill, if a police officer has a reasonable suspicion that someone is an illegal immigrant, they can demand identity papers. Specifically, I mean, what, besides skin color, would give somebody, a cop, a reasonable suspicion?

KAVANAGH: Well, first of all, they can't demand identity papers. There's no requirement that people have I.D. or carry I.D. in this bill.

This bill is, very simply, an extension of a 50-year-old U.S. Supreme Court-created police tool called stop and question to the crime of being in the country illegally.

COOPER: In this case, what's interesting about this bill is, you are defining the crime as just being illegal. So...

KAVANAGH: That's correct. And that makes the hurdle very high.

There aren't going to be large numbers of people picked up under this -- this -- this particular procedure, because it is difficult to get true reasonable suspicion. But I trust professional police officers to obey the law. And it will be used sparingly in this case.

COOPER: In -- what's interesting is, on the one hand -- and the supporters of this bill saying, look, this is empowering police officers -- and you're a former police officer, so I defer to you on this -- but this is empowering police officers.

On the other hand, though, this bill allows citizens to sue the police, local law enforcement or local government if they feel that -- that this -- that this law is not being executed with enough vigor.

KAVANAGH: Well, not -- not a matter of degree.

If a citizen believes that a city has instituted a sanctuary policy, then that citizen is allowed to sue, but citizens sue cities and towns for everything. This simply gives them that power. But, because we wanted to deter frivolous lawsuits, we put in loser pays. Most people will think carefully before they put their own wallets on the line.

COOPER: But it's certainly going to cost an awful lot for cities to be fighting off lawsuits. I mean, on the one hand, you're saying you support the police. On the other time, you're saying that citizens can be able to -- should be able to sue if they think the law enforcement isn't doing their job.

KAVANAGH: And -- and, if the citizen is wrong, if it's frivolous, then the city will recover all the court costs from the citizen.

But we're not suing the cops, by the way. And the street cops like this law. All -- the unions are the ones supporting it. It's the politicians and the police chief appointees who are the ones who oppose this law.

COOPER: Do you think the -- the governor's going to sign it?

KAVANAGH: Absolutely. She has a long history of opposing illegal immigration.

And a Rasmussen poll just came out. Seventy percent of likely voters in Arizona support this law. And I suspect, across the country, the figures are similar. People are fed up with the lack of any enforcement and illegal immigration by the federal government. We have no choice but to fill the void that they have created.

COOPER: I still don't see the language, though, in the actual bill, in which you define what reasonable suspicion of being an illegal immigrant is. And I know you -- you have given an example of, OK, someone's leg sticking out of a vehicle traveling down a highway.

But a group of men standing near a building, you know, ostensibly looking for work, they could be -- they could be questioned.

KAVANAGH: No, they could not. That's not reasonable suspicion.

You know, the reasonable suspicion for bank robberies, for muggings, for any of these crimes is not defined in statute. It's defined as, police do these things, the courts review them, and they determine what is reasonable. And we already have a large body of immigration experience. We have officers who have special training from ICE. ICE officers are trained to detect these things.

COOPER: But those are all behaviors and actions you're talking about, commissions of crimes. KAVANAGH: Yes, absolutely, yes. And that's -- and that's what would happen here. Like I said, running when you see the police. You know, the person opens up his wallet, he says he's here illegally, he says he has immigration papers. The officer says, oh, where did you get them? What's the form number? What color is the form?

COOPER: So, if somebody runs...

KAVANAGH: The person begins to give you wrong answers.

COOPER: So, if -- if a Latino person who's shabbily dressed runs when they see the police, they can -- they can be stopped because that's suspicious?

KAVANAGH: That alone would not be suspicion to hold them.

Let me make one other point...

(CROSSTALK)

COOPER: No, no, but you would say that -- but that is enough to actually stop them and talk to them? I mean, that's what you just said.

KAVANAGH: I would say that's kind of a borderline situation.

I think you have to look at the totality of circumstances. If the person were, you know, coming out from behind a building, and the police officer approached him and the person ran, then I think you're going to run after him. If you just turn the corner and the person happens to be a half-block away and runs, then I don't see any suspicion there at all.

COOPER: So, how does this not just affect Latinos in -- in a state like Arizona?

KAVANAGH: Well, police can stop and question anybody.

Now, obviously, you're going to have more Latinos in this situation, because we don't have that many Norwegians and Chinese crossing the border illegally. But that's a matter of geography, not racial profiling.

COOPER: But you can hold somebody and actually take them in if they can't produce valid documentation?

KAVANAGH: No, no, you cannot. Under reasonable suspicion, you are only allowed to briefly detain them in questioning. If the additional questioning doesn't produce evidence that raises the level of proof from reasonable suspicion to probable cause, then you must release them.

COOPER: So...

KAVANAGH: You can only arrest somebody if you have probable cause, which is a very high standard. That's why there will be no abuse with this law, unless it's an abusive cop who lies. But then the situation is not a bad law. It's a bad cop.

COOPER: In case you were wondering what I was doing there, I was giving a cue to the director at one point during the interview. That's what you saw me doing with my hand.

Let us know what you think about the interview. Go to AC360.com, where the live chat is up and running.

After the break, the other side: the protests, the outcry, those who say what this bill is, is essentially racial profiling. We will talk to some folks ahead.

And later: pictures of the inferno that destroyed an oil rig, the search for 11 missing workers, and the race to stop a river of oil now flowing into the Gulf of Mexico. We will talk to the man who took these pictures, one of the first rescuers on the scene.

(COMMERCIAL BREAK)

COOPER: Protesters hit the streets today, marching against Arizona's bill that would give police the power to stop anyone they reasonably suspect of being an illegal immigrant. These are students, an estimated 2,000 or so, who walked out of school in Phoenix, trying to pressure Arizona's governor to veto the bill. She's expected to sign it.

A lot of questions about it, including, is it constitutional, how would you enforce it without profiling, and the "Raw Politics" of it all.

Joining us now, "In Session" contributor Sunny Hostin, also Cathy Areu, publisher of "Catalina" magazine, which focuses on issues important to Latinas.

Thanks, both, for being with us.

Sunny, what about this? I mean, the legislator -- we just talked to him -- seemed like a nice guy. He's a former police officer. He says the standard for stopping people is high and police are not just able to stop someone if they think they're an illegal -- illegal immigrant.

SUNNY HOSTIN, CNN LEGAL ANALYST: Well, listen, that's nonsense.

This is basically legalized racial profiling. Reasonable suspicion means that you have a reasonable suspicion that someone has either committed a crime or -- or is about to commit a crime.

And what other way can you under -- you know, have a reasonable suspicion that someone is an illegal immigrant, other than the fact that the person is Latino? Listen, I'm Latino, so does that mean, when I'm driving in Arizona with my children, that a police officer can just stop me based on what I look like? That is what this bill allows.

COOPER: But -- but he says, no, it doesn't allow that. It would be if you were driving along and there was something suspicious about your vehicle, maybe there was, you know -- you were in a pickup truck and there were a bunch of people sitting in the back, hidden, or that -- that, you know, if a bunch of Latino people in Arizona were lined up looking for a job, day laborers, the police wouldn't just go over to them and ask them for information.

HOSTIN: And that is inaccurate. I mean, in practice, in actual practical situations -- and, again, I was a prosecutor. I prosecuted a lot of drug cases based on reasonable suspicion, where an officer stopped someone because they believed that this person fits some sort of profile of being a drug dealer.

This is exactly the same thing. Officers would be allowed to stop someone based on what, in their mind, they believe is a reasonable suspicion that this person is an illegal immigrant. What other basis would you have for stopping someone, other than the fact that the person was Latino?

I mean, the voters in Arizona -- 12 percent of the voters in Arizona are Latino. So, they're getting away with appeasing the majority. So, because we don't have a big Latino voice in Arizona, they think they can get away with this.

Unfortunately, all of the Latinos around the country are paying attention. MALDEF, NCLR, LULAC, the largest Latino groups around the country are voicing their opinions, and we're letting Jan Brewer know, the governor, Governor Brewer know that this is racial profiling, and the Latinos around the country are not going to let this slide.

COOPER: Sunny, the other thing that the legislator says -- and there are a lot of folks who agree with him in Arizona -- is that, look, this mirrors federal legislation, that police can stop and talk to people -- can stop and talk to them wherever they want.

HOSTIN: That's just not accurate.

This is really something that is based, I think, on the body of law for reasonable suspicion in criminal law, not federal immigration law.

(CROSSTALK)

COOPER: Right. They're saying this -- he's saying this based on Terry vs. Ohio, which allows police, when they suspect a crime has occurred, to talk to people.

HOSTIN: Right. And that is a Terry stop. That is traditionally used in criminal law, state criminal law, not federal immigration law.

That is just not true. It is inaccurate. And, as a former law enforcement officer, he should know that. And I have got tell you, this law embarrasses me, as a former federal law enforcement officer.

COOPER: It's also interesting, Cathy, because it does allow people to sue their local governments, and law enforcement...

AREU: Yes.

COOPER: ... if they feel that the police are not doing this with enough vigor.

AREU: Well, you have so many people right now that are so upset about immigrants. I mean, so many people are upset about social issues, I think, because we have our first African-American president, so they have to be upset about social issues. They claim it's economic and they claim it's so many others reason.

COOPER: But, look, but people are concerned about illegal immigration. There's a huge issue, obviously, in Arizona.

AREU: But why? It's down 20 percent this year. Illegal immigration in Arizona is down 20 percent this year. So, now they're more upset than ever? They have no reason to be more upset than ever, because it's down 20 percent.

COOPER: Well, they say there are huge crime issues. And there was a very high-profile murder of an Arizona rancher recently.

AREU: Right. So, we're going to pull people over because of the color of their skin while they're driving through town, and, if they don't have the proper papers, we're going to be able to arrest them or question them.

COOPER: Sunny, the legislator pointed out that, look, sure, people can sue their local governments, but anybody can do that, and, in this case, they are going to have to pay for the lawsuit, if, in fact, it doesn't go through.

HOSTIN: I just don't see that as a -- as a deterrent. And, again, what would be the standard for an American to decide that their, you know, state or their city wasn't enforcing a law? This is unprecedented, Anderson. And I got to tell you, I agree, this is...

(CROSSTALK)

COOPER: Do you think it would stand up to constitutional scrutiny?

HOSTIN: No way. I mean, we have, as Americans, the right to be protected against governmental unreasonable search and seizure. If this law is passed -- and I agree, I think the governor will do that -- it is going to be subject to immediately -- immediate, rather, constitutional challenges based on the Fourth Amendment. It's a -- it's a right that every single American has, and every single American will be subjected to this, not only in Arizona.

This could be precedent for this law being passed in every state.

COOPER: If this got passed...

HOSTIN: And people should be very worried about this.

COOPER: If this got passed in Arizona, would you go to Arizona?

HOSTIN: I would go, and I would be subjected to being stopped, racially profiled, and terrorized with my children in the car, with my husband in the car, and -- being in the car.

COOPER: Cathy, I saw -- I saw you shaking your head. You wouldn't go?

AREU: I wouldn't go. I don't think you should go. I don't think any American should drive through Arizona if we could all be stopped because of a reasonable suspicion that we are illegal immigrants.

Would you go? I don't think any American should go. It wouldn't be safe. I think that driving through Arizona today would be like going through Alabama in the '60s. I think Governor Brewer is acting like Governor Wallace. I think it's not a safe place to be if you're not a certain skin color.

As always, a lot more material online at AC360.com, where, tonight, we posted a link to the full text of the bill we have been talking about, so you can read it for yourself, make up your own mind.

Up next, we're going to talk with a ship's captain who took these remarkable pictures -- or took these remarkable pictures, I should say, one of the first people on the scene of that oil rig explosion and fire that may have killed 11 people. It's now spilling hundreds of thousands of gallons of crude into the Gulf of Mexico.

Also, Dennis Quaid on his twins who nearly died, the medical mistake that nearly killed him, and why his story, sadly, is far from unique. If someone you love is going to the hospital, you will want to watch this.

(COMMERCIAL BREAK)

COOPER: Tonight, new details on that massive oil rig explosion off the coast of Louisiana. Officials now fear the 11 workers missing since Tuesday's explosion may have been unable to escape when the blast occurred. Take a look at these images. I mean, that thing is just going up -- 126 people were on board when the rig exploded. Remarkably, only 17 suffered injuries serious enough to require evacuation by helicopter. The remaining 94 either made it to shore or to another vessel relatively unscathed.

Captain Michael Roberts was one of the first responders on the scene. He also took the remarkable iReporter video -- iReport video that you've just seen.

He joins us now from Atlanta.

I mean, thank -- thank goodness you were near enough to kind of respond as quickly as you could. When did you -- what did you see when you first arrived at the scene?

At that time, it was still dark, but you could pretty much see it ablaze. I mean, it sort of resembled, I guess, the sun coming over the horizon.

COOPER: Wow. So, you could see it from far away? It looked like the sun coming up?

ROBERTS: Yes, sir. Yes, sir. It was -- it was plainly visible for at least 20 nautical miles out.

COOPER: Wow.

And, when you got up close, what was it like?

ROBERTS: Well, once we first got there, we were asked to perform -- well, help in the search-and-rescue effort.

So, we initially, at that time, started running a search pattern, based on the degrees that were given. As far as the degree that the current was running and the speed that was running, it was stated, I think, at 220 degrees at 0.8 knots. So, based on that information, my vessel, as well as other vessels, started a search pattern based on that information.

And we assisted with that search-and-rescue effort as long as they needed us to.

(CROSSTALK)

COOPER: And, then, I know there was a time when you basically were doing relays of getting up close, trying to fight the fire, and then you would have to pull away because it was so hot. I mean, how hot was the fire, from your vantage point?

ROBERTS: From our proximity to the rig, I mean, it was very hot. It was to the point where vessels were only able to stay in that close proximity for a limited amount of time, some vessels able to stay longer than others, but, from the footage you see overhead, at times, you will see some vessels close, some vessels far back.

COOPER: So, you would bring -- you would bring your vessel up to try to help fight the fire. I mean, you could feel the heat on you? You could feel the -- the boat heating up?

ROBERTS: Yes, sir.

At no time while in that close proximity did the interior temperature of my vessel's bridge go under 77 degrees. And that's on the interior. If you stepped outside, you would probably be able to -- and that's the reason why the clips are in short nature, because you would only be able to step outside for a limited amount of time...

(CROSSTALK)

COOPER: So, the heat was so intense, it would drive you back inside.

Had you ever seen an explosion like this before?

ROBERTS: Never. I have been doing this 13 years, and I have never seen anything of this magnitude in my tenure.

COOPER: Were you surprised the rig sunk?

ROBERTS: Honestly, no, not from -- not from what I saw there at the scene.

When we first got there, it appeared that it was listing already, maybe about 30 degrees. Further in the day, that list increased to at least 70-, 75-, 80-degree list. It was pretty apparent that it was going to go.

COOPER: Well, again, I mean, just remarkable that you were close enough to respond. And -- and I know there are a lot of people who are thankful that you did.

And our thoughts certainly go out to those missing folks who are still out there.

Michael Roberts, I appreciate you coming on. Thank you.

ROBERTS: Thank you.

COOPER: A lot of other stories happening tonight.

Joe Johns joins us with a 360 news and business bulletin -- Joe.

JOE JOHNS, CNN SENIOR CORRESPONDENT: Anderson, a tornado spotted in Texas tonight, this video shot southeast of Dallas near the town of Goodnight. There are no reports of injuries or damage, but, from Texas north to Nebraska, this danger is not over. The same weather system is expected to move into the southeast tomorrow.

In Manhattan, President Obama calling on Wall Street to accept new regulations, and urging Senate Republicans to help pass them. The measures could come up for a vote early Monday.

The president of Georgia says his country has intercepted a shipment of uranium and is directing some of the blame on Russia. Russia says he's lying. It's the latest flare-up between the two hostile neighboring countries.

Heading to Capitol Hill next week, Fabrice Tourre, or as the Goldman Sachs executive called himself in e-mails, the "Fabulous Fab." He and his boss, Lloyd Blankfein, will testify at a Senate committee hearing Tuesday -- Fab Fab and Goldman already facing a lawsuit from the SEC.

And here comes the sun like you have never seen it before. These are high-definition images from a new NASA telescope showing a massive solar flare with the power of 100 hydrogen bombs. The Solar Dynamics Observatory will collect data for the next five years and could give fresh insight into how the sun works.

COOPER: Wow.

JOHNS: That's just amazing, isn't it?

COOPER: Incredible. I have never...

JOHNS: Wow.

COOPER: Just unbelievable images.

Joe, thanks. We will check in with you shortly.

Up next: Dennis Quaid, who almost lost his newborn twins to the kind of medical mistake that takes tens of thousands of lives every year. He says, mistakes are made. Doctors, he says, tries to hush -- try to hush them up -- his crusade to change that just ahead.

And later: A Hollywood producer takes at rip with his wife to Mexico, apparently a last-ditch attempt to save their marriage. Now she is dead, he is a murder suspect in a place where the accused are presumed guilty, not innocent.

(COMMERCIAL BREAK)

COOPER: Tonight: Dennis Quaid on his kids' near-death ordeal -- his newborn twins at just 12 days old. The infants were in the hospital, and give a -- given a massive drug overdose.

Now, simple -- simple deadly mistakes like that kill more than 90,000 patients every year. Dennis Quaid is trying to change that. We are going to hear from him in a moment.

But, first, Randi Kaye takes an "Up Close" look at the hospital nightmare that changed the actor's life forever.

(BEGIN VIDEOTAPE)

RANDI KAYE, CNN CORRESPONDENT (voice-over): It was November 2007, less than two weeks after Dennis Quaid's twins were born, when the actor says the nurse caring for them nearly killed them.

The babies, Thomas Boone and Zoe Grace, had been readmitted to Cedars-Sinai Hospital in Los Angeles for a staph infection. But the nurse unknowingly gave the twins 1,000 times the recommended dose of the drug heparin, a blood thinner. Quaid and his wife were in the room, but didn't know anything was wrong until the next day, when they found their newborn bleeding profusely.

DENNIS QUAID, ACTOR: Their now water-thin blood had the real possibility of hemorrhaging through a vein or artery, causing massive brain damage or failure to one of their vital organs.

KAYE: Quaid says the twins were supposed to receive 10 units of heparin, but instead got the adult dosage of 10,000 units, a massive overdose that turned their blood thin as water.

(on camera): How could this happen? Quaid says, both the pediatric dose and the adult dosage of heparin have similar labels. For the next 41 hours, doctors scrambled to save his children.

QUAID: At one point, as the doctors tried to clamp a bleeding wound in the remnant of T-Boone's umbilical cord, blood spurted six feet across the room and splattered on the wall.

KAYE: It was the most frightening night of his life. They'd worked so hard to have children. First, trouble conceiving, then miscarriages, and now this.

QUAID: And our babies could have died that night.

KAYE: Three other babies did die in Indianapolis, a year before. Just like the Quaids, the six infants in that case were given adult doses of heparin. Half of them died.

QUAID: They recall automobiles. They recall toasters. They even recall dog food. But Baxter failed to recall a medication that, due to its labeling, had already killed three infants.

KAYE: Baxter International, one heparin manufacturer, told CNN it had redesigned the drug's vial before the Quaid scare to help doctors identify the right dosage. But Baxter did not recall the older vials, so they were still being used at Cedar-Sinai, where Quaid's children were treated.

Quaid sued Baxter for negligence, but the case was dismissed.

(on camera) Quaid and his wife reportedly settled with Cedar- Sinai Hospital for $750,000, but they say this isn't about the money. This is about protecting patients and doing something about the nearly 200,000 Americans who reportedly die each year due to medical errors.

Randi Kaye, CNN, New York.

(END VIDEOTAPE)

(BEGIN VIDEOTAPE) COOPER: Well, since that nearly fatal mix-up, Dennis Quaid and his wife, Kimberly, have channeled their outrage into action. In 2008, they founded the Quaid Foundation, an organization dedicated to preventing medical mistakes, and just recently they partnered with the Texas Medical Institute of Technology on a new documentary. It's called "Chasing Zero: Winning the War on Health-Care Harm," and it airs this Saturday on the Discovery Channel.

Dennis Quaid and Dr. Charles Denham, chairman of the institute, join me now for the "Big 360 Interview."

Thanks, both for being with us. Dennis, let me start off. How are the twins doing now? Did they suffer any long-term consequences?

QUAID: No. Thank God, they didn't. The twins are doing great. In fact, they're probably ahead -- of course, I'm a proud parent -- so they're probably ahead of their development, really. And we just couldn't be happier.

COOPER: Dennis, take us back to that day when you got the news. I mean, what went through -- what went through your mind?

QUAID: Well, it was -- it was the most difficult day of mine and my wife, Kimberly's, life, really. Our twins were given 1,000 times the dose they should have received of a blood thinner, heparin, and were bleeding out of every place they'd been poked or prodded. And there was a real danger of them hemorrhaging through a vein or artery and causing brain damage or damage to a vital organ.

COOPER: And -- I mean, so what did the doctor first say to you? I mean, how did they break that news?

QUAID: Well, they took us -- we -- they took us into a room and told us what had happened and also told us that this same incident had occurred in a hospital in Indianapolis just a year before, that it killed three children and injured several others. And from there, this -- it was a 41-hour event that, luckily, ended with the twins surviving.

COOPER: And Dr. Denham, I mean, how often does this happen? How often do medical mistakes occur? How big a problem is it, really?

DR. CHARLES DENHAM, CHAIRMAN, TEXAS MEDICAL INSTITUTE OF TECHNOLOGY: It's a staggering problem. We have the equivalent now of about 20 747s going down every week in America. If you add infections, which are 100,000 preventable deaths, and most of those are preventable, to the former number of 100,000, that's 20 747s going down. But it's spread over 57 hospitals.

QUAID: It comes out to about 200,000 people a year who are dying needlessly, preventable.

(END VIDEOTAPE)

COOPER: We're going to have more with Dennis Quaid on his twins and his newfound mission to make hospitals safer for everyone. Also, a sneak peek at his eye-opening documentary about the simple but potentially deadly mistakes hospitals make.

And a gruesome murder in Cancun. Why a former "Survivor" producer is the lead suspect and the explosive new e-mails that may provide a motive.

Outraged by the tens of thousands of patients killed every year by simple medical errors. Quaid's newborn twins were accidentally given an overdose of the blood thinner heparin in 2007. Thankfully, they're healthy now. He's teamed up, though, with Dr. Denham to raise awareness on medical errors in the new documentary, "Chasing Zero: Winning the War on Health-Care Harm." Their film premieres this Saturday on Discovery. Here's a quick look.

(BEGIN VIDEO CLIP)

QUAID: Our little twins were the victims of preventable harm. They came very, very close to dying.

I have found out two shocking truths. First, the staggering magnitude of health-care harm that occurs in our country. Second, how much of that harm is absolutely preventable.

(END VIDEO CLIP)

COOPER: Dennis, you were saying before the break, 200,000 deaths a year in the United States. You say that zero harm is the goal, but I mean, humans make mistakes. Is there -- is it really possible to have a day when no patient is harmed?

QUAID: Well, that's what we're after. Of course, human error is always going to occur, but we can get that number as close to zero as possible.

We really -- we compare the aviation industry to the medical industry, really. We would -- we would like to see an NTSB-like organization in health care that investigates accidents as they occur and can go to the -- find the problem and then take measures on a national scale to solve them.

COOPER: Doctor, do you think that would work?

DENHAM: Well, we have really substantial evidence to show that we can dramatically drop and really reduce these preventable errors, right down to zero. And the National Quality Forum's safe practices was released last week -- and Dennis was part of releasing them at the National Press Club -- have shown that you can actually drop many, many of these to zero. We don't have bad people; we have bad systems.

COOPER: So how do you go about doing that? I mean, how do you drop them to zero?

DENHAM: Well, basically, what -- it's amazing. There are so many simple things that we do every day in health care that could be more standardized, with basic safe practices and predictable outcomes. And this has been established in many studies. Leading experts agree that many of these areas could be dropped almost to zero.

COOPER: You've talked in the past about a conspiracy of silence among medical providers when errors happen, that they kind of circle the wagons. Is that, you think, because they're afraid of being sued?

QUAID: Well, I think it's a number of issues, but, yes, I think that what it gets down to, to begin with, we were met at the door when this incident occurred with our twins. You know, first by the doctors and then immediately by risk management, which was really to control liability.

And there is a, as I said, a conspiracy of silence that happens because of that fear of liability. Caregivers, which I think is wrongly so, are criminalized for making mistakes that are basically predictable human error.

COOPER: And Doctor, I mean, it sounds so reasonable, OK, you know, obviously, try to eliminate as many mistakes as possible, but there is resistance, I mean, to your efforts.

DENHAM: Well, you know, there is, and that's why we -- that's why we put together the documentary, and we're so grateful for Dennis to help us gain the attention.

We have a number of winners and role models in this documentary that have shown they can face -- we talk about fear being the Goliath and that they have to activate their inner David, the leaders of hospitals. And the typical hospitals at the front line are pretty resistant, and the status quo is really the enemy. It's not bad people; it's bad systems.

COOPER: And Dennis, going beyond, obviously, the big picture of what you're trying to do, what's your advice to folks who find themselves in the hospital or dealing with a situation where they're not sure what's going on? What's your best method for surviving a hospital stay?

QUAID: Well, No. 1, never stay in a hospital alone. Always have a friend or a loved one there with you in the hospital.

DENHAM: A couple of other things: when patients leave the hospital, they should make sure to get their medical records and be able to be part of the team to get those records to the next caregiver.

Ask everybody to wash their hands, who they're working with. And when you get home, make sure that you have the list of your medicines and that you're taking the right medicines and reconciling it. Those are simple things that everybody can do.

COOPER: A quick program note: on a night with oil spilling into the Gulf of Mexico, remarkable photos of the sun, a special Earth Day edition of "Planet in Peril" is coming up in the next hour. Part of it is, of course, my up-close encounter with Great White Sharks. Take a look.

(BEGIN VIDEOTAPE)

COOPER (voice-over): When Great White Sharks start to circle your boat, the feeling is unsettling. Fifteen feet long, thousands of pounds, these are the animals of so many nightmares.

UNIDENTIFIED MALE: This is the famous shark Eddie (ph).

COOPER: We've come to dive with these Great Whites, to get an up-close look at them and see the battle that's being waged around them.

UNIDENTIFIED MALE: Please, do not go down unless we tell you to.

COOPER: Mike Rutsin (ph) takes tourists cage diving with Great White Sharks off the coast of South Africa.

UNIDENTIFIED MALE: And then you can lean back and become comfortable.

COOPER: It's become a big business, but it's also, he also, a conservation effort. He thinks if people can see these endangered animals under water, they'll learn to appreciate them and want to help protect them.

Cage diving, however, is highly controversial. We'll tell you why in a second, but right now the water is filled with blood and fish parts called chum, and the Great Whites have arrived.

(on camera) So any recommendations for what to do?

UNIDENTIFIED MALE: Well, basically, don't scare the sharks. You go into the water... COOPER: I'm not worried about scaring the sharks. It's usually the other way around, I think.

(voice-over) After we get used to being in the water with the sharks, inside a cage, we get the chance to do something that few others ever have. We'll go swimming with Great White Sharks without a cage.

(END VIDEOTAPE)

COOPER: It's pretty cool. "Planet in Peril," Earth Day edition, at the top of the hour in about 15 minutes.

But up next, a vacation turns deadly for a reality TV producer's wife. Now the husband cannot leave Mexico until police are done with their investigation. The mystery ahead.

And a "360 Follow." Network executives take action after threats are made against "South Park" producers, and the producers are saying they were censored. We have the latest on that.

(COMMERCIAL BREAK)

COOPER: New developments tonight in a vacation murder mystery. Bruce Beresford-Redman, a former producer for the CBS reality show "Survivor," is the lead suspect in the death of his wife Monica in Cancun, Mexico.

A, quote, "very close friend" of Monica has sold e-mails to a gossip site. So how much of a close friend she was, we don't really know. E-mails reportedly between the producer, his wife, and his mistress. If authentic, they may provide a motive for a murder that's left friends, family, and Hollywood reeling.

Ted Rowlands has the story in tonight's "Crime & Punishment."

(BEGIN VIDEOTAPE)

TED ROWLANDS, CNN CORRESPONDENT (voice-over): Bruce and Monica Beresford-Redman checked into the Moon Palace in Cancun three weeks ago, March 31. It's a sprawling 123-acre oceanfront resort, with security checkpoints at every entrance.

(on camera) The couple brought with them their 5-year-old son and 3-year-old daughter, but relatives say this wasn't a normal family vacation. They say it was planned last-minute as an attempt to save a troubled marriage.

(voice-over) Six days after arriving, on the night of April 5, there was a fight so loud in the family's room the front desk called. Mexican authorities say Bruce told them everything was fine. The next morning, he reports Monica is missing.

(on camera) As the search for Monica started here in Cancun, Bruce called his parents to come and get the children. He also called Monica's sister in California. JEAN BURGOS, VICTIM'S SISTER: And I asked, "What? How come she's missing?"

And he said, "Well, she went out yesterday morning to town to do some shopping, and she never came back."

And I say, "What? Where are the kids?"

"Oh, the kids are with me."

My sister would never leave the kids with him for a whole day, ever.

ROWLANDS (voice-over): Hotel security records show Monica never left the property, so the search was centered at the resort. After two days, on what would have been her 42nd birthday, Monica's body was found on the hotel grounds. Investigators say she was naked, her clothes placed alongside her body.

(on camera) This is where her body was found. Basically, it's an opening to an underground sewage system, which runs throughout the entire resort. The family was staying in a room right over here in this building up on the second floor.

(voice-over) There's no video surveillance in this part of the resort, but according to investigators, the family's hotel card key was used in their door 11 times between midnight and 6 a.m. in the hours before Monica was reported missing.

Her husband, Bruce Beresford-Redman, has surrendered his passport. He was told he can't leave Mexico until the investigation is over.

His parents, who have temporary custody of the children, released a statement, saying in part, "We know our son loved Monica and would never have harmed her."

BURGOS: Monica was loved, and she was an amazing person.

ROWLANDS: Monica's mother and sister arrived in Mexico Tuesday. They brought with them e-mails they say show that Monica's husband had a recent affair and that the marriage was in trouble.

UNIDENTIFIED MALE: What's it been like for you and your family?

BURGOS: Hell.

UNIDENTIFIED MALE: What message would you say to Bruce if you could?

BURGOS: No comment.

ROWLANDS: The lead prosecutor in the case told us the e-mails provide very little in terms of the investigation. They're waiting for the forensic test results before they decide on whether or not to charge Beresford-Redman. (END VIDEOTAPE)

COOPER: And what kind of jail time could he be facing if charged and convicted of murder?

ROWLANDS: Well, if he's convicted of premeditated murder, which would be the maximum sentence in Mexico, he's only looking at 25 years.

If a judge decides, though, that it wasn't premeditated -- this, of course, is if he is arrested and convicted -- he could serve as little as ten years.

The Mexican system much different than the U.S. system, Anderson. There's no jury here. There's no oral arguments in court. And here, you are presumed guilty unless you can prove that you are innocent. So if he's arrested, most likely, he will spend time in a Mexican jail.

COOPER: And where is he now?

ROWLANDS: Well, that's the big question. Nobody is quite sure. He is keeping a low profile. He can't leave the country. The U.S. consulate says that they are in contact with him and his family. And, if Mexican authorities are looking for him, it is assumed that they will help the Mexican authorities get in contact with him.

COOPER: All right. Ted Rowlands on the scene. Ted, thanks.

Coming up next, "South Park" is threatened and the creators censored after portraying the Prophet Muhammad hidden inside a bear costume. The latest when we continue.

And a special Earth Day edition of "Planet in Peril." We'll take you up close to show you how our world is changing.

(COMMERCIAL BREAK)

COOPER: All right. Let's take a look at some of the other stories we're following. Joe Johns back with a "360 Bulletin" -- Joe.

JOE JOHNS, CNN CORRESPONDENT: Anderson, the producers of "South Park" say Comedy Central removed 30 seconds of dialogue from this week's show after a radical Muslim group suggested that the program's depiction of the Prophet Muhammad could lead to violence.

According to the show's creators, the cut dialogue included a speech about intimidation and fear. The controversy began when last week's episode depicted Muhammad in a bear costume.

A missing Ohio mother whose disappearance triggered a nationwide search has been found safe in Florida. Tiffany Tehan vanished over the weekend. She was later spotted on a surveillance camera in a Miami Beach convenience store with a male companion.

Eleven suspected pirates face prosecution here in the U.S. for attacks on Navy ships, including the USS Ashland near Somalia. The cases will be prosecuted in Norfolk, Virginia.

And check this out. A runaway saw blade rolls across a yard and into the side of a house. A construction worker chased after it. This is a bizarre moment, caught on a home security camera near Cleveland, Ohio. The blade left a three-foot gash in the house, and you can really only laugh at that, because nobody got hurt.

COOPER: Can you imagine the panic of the guy -- that guy's mind when he first sees that blade going off?

JOHNS: Good grief. Anything could happen, yes. It's good it didn't come after him.

COOPER: All right, Joe. For tonight's "Shot," an odd and very funny musical duet. William Shatner hits the stage with Taiwanese Internet singing sensation Lin Yu Chun to belt out their version of Bonnie Tyler's classic, "Total Eclipse of the Heart." Watch and enjoy.

JOHNS: Right. But -- but what's his name, Shatner is either flat or sharp at all times.

COOPER: Not since Emo Phillips have I seen such a hairdo, though, on a young man there.

Yes. So that's from "Lopez Tonight," of course, on our sister network, TBS. Lin has been called the next Susan Boyle after competing on Taiwan's TV talent show "Superstar Avenue." It's a great name, a snazzy name for a show.

William Shatner, well, you know...

JOHNS: "Star Trek".

COOPER: ... who he is. "Star Trek," exactly. And "T.J. Hooker."

All right, Joe, thanks very much.

Just ahead tonight, a swim with sharks without a cage. Part of our special Earth Day edition of "Planet in Peril." We'll be right back.